JP2015194600A - Image forming device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To eliminate incomplete start processing when power supply to an image forming device is stopped, and to reliably and normally start a circuit unit at the next start.SOLUTION: An image forming device includes: a circuit unit that performs start processing and operates when power supply is started; an operation unit that accepts a switching instruction between a normal mode and a power saving mode; a power supply code connected to a supply source; a detection unit for detecting whether or not power is supplied to the image forming device; a power control unit that controls on/off of power supply to the circuit unit, supplies power to the circuit unit in the normal mode, stops power supply to all or part of the circuit unit in the power saving mode, and communicates with the circuit unit by starting power supply to the circuit unit in response to a transition instruction; and a power supply unit that supplies power to the circuit unit to which power supply is made in an on state. When the stop of power supply to the image forming device is detected, the power control unit does not start the circuit unit even if it accepts a transition instruction.

Description

  The present invention relates to an image forming apparatus capable of switching between a power saving mode and a normal mode, which is a mode in which the image forming apparatus can be used, by operating a switch or the like.

  In general, image forming apparatuses such as multifunction peripherals, copiers, printers, and facsimiles are connected to a power source to receive power. For example, the power cord of the image forming apparatus is connected to an outlet, and the image forming apparatus is supplied with power from a commercial power source. Normally, in an image forming apparatus, when the main power is turned off with a switch or the like, the main power is turned off after necessary processing such as information protection is performed. However, the power supply to the image forming apparatus may stop unintentionally due to factors such as a power failure or a power cord caught on the user's foot. Therefore, Patent Document 1 discloses an image forming apparatus that protects information during processing even when a sudden power supply stop such as a power failure occurs.

Specifically, Patent Document 1 discloses an active filter that converts an AC voltage into a DC voltage, a load control unit that converts the DC voltage converted by the active filter into a voltage of a predetermined level, and controls the load. A power supply control means for controlling the operation of the DC / DC conversion means, including a first DC / DC converter as a DC / DC conversion means to be supplied and a second DC / DC converter to be supplied to the load control means, And detecting means for detecting disconnection of the AC power supply, and the power supply control means supplies the voltage to the load control means by the DC / DC conversion means when the detection means detects the disconnection of the AC power supply. To maintain the voltage supply to the load control means by the second DC / DC converter for a certain period of time. It stops the operation of the converter. With this configuration, the electric charge accumulated in the capacitor of the active filter is consumed only by the second DC / DC converter, and the supply of voltage to the load control means is continued for a certain time (Patent Document 1: Claim). 1, claim 2, paragraph [0008]).
JP 2002-359970

  A certain amount of power is required to keep the image forming apparatus in a printable state (hereinafter referred to as “normal mode”). Therefore, normally, the image forming apparatus is equipped with a power saving mode in which power supply to a circuit unit or a load (such as a motor or a sensor) other than the circuit unit is stopped. The circuit section here is an integrated circuit in the image forming apparatus, a chip dedicated to a specific process, or a storage device such as a memory. In the power saving mode, the image forming apparatus is in a state where printing cannot be performed immediately, but the power consumption of the image forming apparatus is smaller than in the normal mode.

  In order to be able to operate the mode of the image forming apparatus, a switch (key) for instructing switching between the power saving mode and the normal mode may be provided. When the switch is operated, power supply is started to a circuit unit such as a control or processing circuit or a memory storage device for which power supply has been stopped. Thereby, the starting process in the circuit unit is started. The circuit unit is initialized and set values are set by the activation process, and the functions of the image forming apparatus such as printing can be used.

  On the other hand, the image forming apparatus is provided with a power supply device that converts electric power supplied from a power source such as a commercial power source to generate one or a plurality of types of drive voltages suitable for a circuit unit in the image forming apparatus. For example, the power supply device rectifies the AC of the commercial power supply, adjusts the voltage, and the like, and generates a voltage for driving a control circuit (integrated circuit) and a memory in the image forming apparatus.

  Generally, a power supply device includes a capacitor, a transformer, and a coil for rectification and voltage adjustment. And the energy is stored in the capacitor | condenser and transformer in a power supply device. For this reason, even if the power supply to the image forming apparatus is stopped due to a power failure or a power cord being disconnected, the circuit units such as the control circuit and memory operate for a certain period of time until the output value of the power supply that gradually decreases falls below the drive voltage value. to continue. The time during which the circuit unit continues to operate depends on the number of circuit units that supply power (the amount of power consumed by the image forming apparatus when power supply to the image forming apparatus is stopped due to a power failure or the like).

  In particular, in recent years, some of the power consumption in the power saving mode is extremely low. In such an image forming apparatus, a control circuit and a memory in the image forming apparatus may continue to operate for several tens of seconds or more after a sudden stop of power supply to the image forming apparatus.

  Here, when the power supply to the image forming apparatus is stopped due to a power failure or the like, the user may perform an operation (an operation of pressing a switch) to instruct to return from the power saving mode to the normal mode without knowing it. is there. At this time, a part of the circuit unit may be alive (continuously driven). In some cases, these conditions overlap, and the power supply to the circuit unit that has stopped power supply is started when the power supply to the image forming apparatus is not supplied. Then, due to the consumption of accumulated energy and the output reduction of the power supply device, the process may end in the middle of the start-up process such as started initialization or setting of setting values.

  For example, due to a decrease in the output voltage of the power supply device, the setting value of the register in the control circuit, communication in the circuit, and reading / writing to the memory are performed in a state where the drive voltage is not normal. It may be registered in memory. Also, initialization and setting value setting may be forcibly terminated due to a decrease in output of the power supply device. Furthermore, there is a case where the circuit itself is damaged due to interruption in the middle of the starting process. Due to these halfway start-up processes, there is a problem that the circuit unit may not be normally started at the next start-up (at the start of the next power supply).

  Note that the image forming apparatus described in Patent Document 1 stores information being processed when the AC power is accidentally turned off, and protects the information. The problem that the circuit unit cannot be started normally cannot be solved.

  In view of the above-described problems of the prior art, the present invention eliminates a halfway start-up process when power supply to the image forming apparatus is stopped, and reliably starts the circuit unit at the next start-up.

  In order to solve the above-described problem, an image forming apparatus according to claim 1 performs a startup process when power supply is started, a circuit unit that operates by receiving power supply, a normal mode, and an image that is more than the normal mode. An operation unit that receives a mode switching instruction between power saving modes that reduces power consumption in the forming apparatus, a power cord connected to an external supply source to receive power supply from an external power source, and the power cord A detection unit for detecting whether power is supplied to the image forming apparatus and ON / OFF of power supply to the circuit unit are controlled, and power supply to the circuit unit is performed in the normal mode. When the power saving mode is instructed to stop power supply to all or some of the circuit units, and the operation unit is instructed to switch from the power saving mode to the normal mode, A power control unit that starts power supply to the circuit unit and exchanges signals with the activated circuit unit, and converts power input to the image forming apparatus via the power cord, and the power cord In a state connected to the supply source, power is supplied to the power control unit to operate the power control unit, and power is supplied to the circuit unit in which the power supply is turned on. A power supply unit, and the power control unit detects a stop of power supply to the image forming apparatus using the detection unit. The power supply to the circuit unit is not started and the circuit unit is not started.

  According to the present invention, it is possible to eliminate a halfway start process when the power supply to the image forming apparatus is stopped. As a result, an incorrect value is registered in the control circuit or memory by setting a register set value in the circuit unit, communication in the circuit unit, or reading / writing to the memory without a normal driving voltage. Things will disappear. Further, initialization and setting value setting are not forcibly terminated due to a decrease in output of the power supply device. Therefore, at the time of the next activation, the control and processing circuits and the circuit unit such as the memory can be activated normally.

It is a model front sectional view showing a schematic structure of a printer. 2 is a block diagram illustrating an example of a hardware configuration of a printer. FIG. It is a block diagram which shows an example of the flow of the electric power generation to each part of a voltage generation and a printer. It is explanatory drawing for demonstrating the electric power supply control with respect to the load part of a printer. FIG. 6 is an explanatory diagram for explaining switching of each mode in a printer. It is a timing chart which shows an example of the flow of starting at the time of insertion of a power cord. 6 is a timing chart illustrating an example of a flow of a voltage drop when power supply to a printer is stopped. 6 is a flowchart illustrating an example of a control flow when a start switch is pressed in a first power saving mode in a state where power supply to a printer is stopped. 6 is a flowchart illustrating an example of a control flow when a start switch is pressed in a second power saving mode in a state where power supply to a printer is stopped.

  Hereinafter, embodiments of the present invention will be described with reference to FIGS. The printer 100 will be described as an example of the image forming apparatus. However, each element such as configuration and arrangement described in each embodiment does not limit the scope of the invention and is merely an illustrative example. The present invention is not limited to the printer 100, and can be applied to other types of image forming apparatuses such as a multifunction machine, a copier, and a FAX apparatus.

(Outline of image forming apparatus)
First, a toner image is formed with reference to FIG. 1, and an outline of an electrophotographic printer 100 (corresponding to an image forming apparatus) will be described. FIG. 1 is a schematic front sectional view showing a schematic configuration of the printer 100.

  As shown in FIG. 1, the printer 100 according to the present embodiment includes, from below, a paper feed unit 2a, a transport unit 2b, an image forming unit 3a, a fixing unit 3b, and the like.

  In the present embodiment, two paper feed units 2 a are provided at the bottom of the printer 100. Each paper feed unit 2a accommodates various types of paper (plain paper, printer 100, OHP sheet, etc.) and various sizes (A4, B5, etc.). The paper feed roller 21 provided in each paper feed unit 2a contacts the uppermost paper among the stacked paper. One of the paper feed rollers 21 rotates during paper feeding. Each paper feed roller 21 is rotationally driven by a driving device (not shown) such as a motor 3M. Then, the sheets are sent one by one to the transport unit 2b.

  The transport unit 2b transports the paper fed from the paper feed unit 2a to the discharge tray 22 through the image forming unit 3a. The transport unit 2b is provided with a guide plate 2323 for guiding paper along the transport path, a transport roller pair 24, a registration roller pair 25, and a discharge roller pair 26. The conveyance roller pair 24 conveys the sheet toward the image forming unit. The registration roller pair 25 sends the paper to the nip between the transfer roller 35 and the photosensitive drum 31 in synchronization with the toner image. The discharge roller pair 26 passes through the fixing unit 3b and conveys the sheet toward the discharge tray 22. Each roller of the transport unit 2b is rotationally driven by a drive mechanism (not shown) including a motor 3M.

  As shown in FIG. 1, the image forming unit 3 a is disposed at a central left position in the printer 100. For example, the image forming unit 3a forms a toner image of an image to be formed based on image data of a document or print setting data transmitted from a computer 200 (personal computer or server, see FIG. 2), and transfers it to a sheet. Do. The image forming unit 3a includes a photosensitive drum 31, a charging device 32, an exposure device 33, a developing device 34, a transfer roller 35, and a cleaning device 36 disposed around the photosensitive drum 31.

  A toner image forming process will be described. The photosensitive drum 31 is rotationally driven in a predetermined direction (clockwise in FIG. 1). The charging device 32 charges the peripheral surface of the photosensitive drum 31. The exposure device 33 scans and exposes the peripheral surface of the photosensitive drum 31 by irradiating the charged photosensitive drum 31 with light (for example, laser light) based on the image data. As a result, an electrostatic latent image corresponding to the image data is formed on the peripheral surface of the photosensitive drum 31. The developing device 34 charges the toner and supplies the toner to the electrostatic latent image. Thereby, the electrostatic latent image is developed as a toner image. The transfer roller 35 is rotatably supported and presses against the photosensitive drum 31 to form a nip. When a sheet and a toner image enter the nip, a voltage having a polarity opposite to the charging polarity of the toner is applied to the transfer roller 35. As a result, the toner image is transferred to the paper. The cleaning device 36 removes and collects residual toner, dust, and the like on the peripheral surface of the photosensitive drum 31.

  In the present embodiment, the fixing unit 3b includes a heating roller 38 and a pressure roller 39 including a heater 37 that generates heat when energized. The heating roller 38 is heated and rotated by the heat generated by the heater 37 in order to heat the toner image. The pressure roller 39 rotates while contacting the heating roller 38. Then, when the sheet enters the nip of the fixing unit 3b, the toner image is pressurized and heated. As a result, the toner image is fixed on the paper. The sheet after fixing is discharged to the discharge tray 22.

  As shown by a broken line in FIG. 1, the printer 100 of the present embodiment includes an operation panel 4 (corresponding to an operation unit) on the upper left side of the front for setting the operation and mode of the printer 100. The operation panel 4 is provided with a liquid crystal display unit 41, a plurality of indicators 42, a plurality of operation keys 43, and the like. The liquid crystal display unit 41 displays various messages such as failure occurrence and error messages. The indicator 42 is a light emitting element (for example, LED), and a plurality of indicators 42 are provided. The indicator 42 lights up and blinks to display various messages such as failure occurrence, printing, and out of paper. Various settings for the printer 100 can be performed by an operation key 43 provided on the operation panel 4. Further, the operation panel 4 is provided with a power saving switch 43a as a kind of operation key, which switches the mode and gradually reduces the power consumption of the printer 100.

(Hardware configuration of printer 100)
Next, an example of the hardware configuration of the printer 100 according to the embodiment of the present invention will be described with reference to FIG. FIG. 2 is a block diagram illustrating an exemplary hardware configuration of the printer 100.

  As shown in FIG. 2, the printer 100 of the present embodiment is provided with a main control unit 1 (corresponding to a power control unit) that controls the overall operation of the printer 100. The main control unit 1 is provided with a CPU 11 as a central processing unit. The main control unit 1 includes a RAM (Random Access Memory), a ROM (Read Only Memory), and a flash ROM, and is communicably connected to a storage unit 5 (corresponding to the circuit unit 100b) that stores data. The ROM and flash ROM store programs and data necessary for various controls. The RAM temporarily develops control programs and data, image data, and the like. The main control unit 1 performs processing using data and programs stored in the storage unit 5.

  Further, the printer 100 according to the present embodiment is provided with a timer unit 12 (timer) for measuring time. The timer 12 measures the time to be measured for control. Note that the time may be measured using the timer function of the CPU 11 of the main control unit 1.

  In addition, the printer 100 includes operations of the engine unit 20 which is a printing unit such as a paper feeding unit 2a, a conveyance unit 2b, an image forming unit 3a, a fixing unit 3b, and a motor 3M that rotates various rollers used for printing. An engine control unit 30 (corresponding to the circuit unit 100b) to be controlled is provided. The engine control unit 30 includes a circuit such as a CPU (not shown) and controls each part of the engine unit 20. The engine control unit 30 also includes a storage element 301 that stores data and programs for print control and communication in a nonvolatile and volatile manner. The engine control unit 30 and the main control unit 1 are communicably connected. Then, the main control unit 1 gives a print instruction to the engine control unit 30. The engine control unit 30 receives an instruction from the main control unit 1 and controls the engine unit 20 using data stored in the storage unit 5 and the storage element 301.

  The printer 100 is provided with an image processing unit 6 (corresponding to the circuit unit 100b). The image processing unit 6 includes a dedicated circuit for image processing (for example, ASIC) and a storage element 62 that stores data, programs, and settings related to image processing. The image processing unit 6 and the main control unit 1 are communicably connected. Based on an instruction from the main control unit 1, the image processing unit 6 performs image processing on the image data used for printing in accordance with the setting for printing. Then, the image forming unit forms a toner image based on the image data processed by the image processing unit 6.

  In addition, the printer 100 is provided with a power supply unit 7 that generates voltages necessary for various circuits inside the printer 100 and supplies the circuits to the various circuits. The main control unit 1 controls the operation of the power supply unit 7 and the power supply destination of the power supply unit 7 (details will be described later).

  The printer 100 is provided with a plurality of sensors 8 (details will be described later). The main control unit 1 recognizes the state of the printer 100 based on the outputs of the plurality of sensors 8.

  The printer 100 is provided with a communication unit 9 (corresponding to the circuit unit 100b) for communicating with the computer 200. The printer 100 includes a communication circuit, and a storage element 91 that stores a communication program and data. The communication unit 9 receives data (for example, image data) indicating contents to be printed and print setting data from the computer 200. The communication unit 9 is communicably connected to the main control unit 1. The communication unit 9 transmits the received data to the main control unit 1 and the storage unit 5.

  The printer 100 is provided with an operation panel 4. The main control unit 1 is connected to the operation panel 4 so as to be communicable. The main control unit 1 controls the display of the liquid crystal display unit 41 and the indicator 42 of the operation panel 4. The main control unit 1 recognizes a touch input to the operation key 43, recognizes a setting by the user, and controls each unit of the printer 100 so as to follow the setting.

  Further, the printer 100 according to the present embodiment is provided with a start switch 10 (corresponding to an operation unit, a power switch) for switching the mode of the printer 100. For example, the activation switch 10 is provided on the front surface or side surface of the printer 100. The output of the start switch 10 is input to the main control unit 1. The main control unit 1 recognizes that the start switch 10 has been pressed. The start switch 10 is a switch whose output changes when pressed. When the start switch 10 is pressed, the main control unit 1 switches the mode of the printer 100 and switches a portion for supplying power in the printer 100 (details will be described later).

(Voltage generation and power supply to each part of printer 100)
Next, voltage generation in the printer 100 and power supply to each part of the printer 100 will be described with reference to FIG. FIG. 3 is a block diagram illustrating an example of the flow of voltage generation and power supply to each part of the printer 100. In FIG. 3, the power supply path is indicated by white arrows.

  The printer 100 of this embodiment is provided with a power cord C2 for receiving power from an external power source (commercial power source). The power cord C2 is connected to the outlet C1. Power is supplied to the printer 100 via the power cord C2. AC power from the outside is input to the power supply unit 7 by the power cord C2. In the printer 100 of the present embodiment, AC power that has once passed through the power supply unit 7 is input to the heater 37. The power supply unit 7 is provided with a drive circuit (not shown) that controls ON / OFF of energization to the heater 37. The main control unit 1 controls output of the heater 37 by controlling energization to the heater 37 by controlling a drive circuit (not shown).

  The primary power supply unit 71 is a power conversion circuit that rectifies and smoothes AC power from the outside and generates a DC voltage. The primary power supply unit 71 includes a transformer, a coil, a capacitor, and a transistor, and includes a switching power supply 71a that performs rectification and smoothing and generates a DC voltage. For example, the switching power supply 71a generates DC 24V. The voltage generated by the switching power supply 71a is applied to the motor 3M. The engine control unit 30 controls the energization of the motor 3M and controls the rotation of various rotating bodies.

  The output of the switching power supply 71a is input to the main controller 1. Thereby, the main control unit 1 can measure the output of the power supply unit 7.

  In the printer 100 of this embodiment, a zero cross signal generation unit 71b (corresponding to a detection unit) is provided. The zero cross signal generation unit 71b generates a zero cross signal for detecting that the voltage value of the AC voltage input from the external power supply (commercial power supply) crosses 0V (zero cross point). The output of the zero cross signal generation unit 71b is input to the main control unit 1. The main control unit 1 determines whether power is being supplied to the printer 100 based on the zero cross signal. Thereby, the main control unit 1 can detect whether or not a power failure or a drop in the power cord C2 has occurred.

  The power supply unit 7 is provided with a secondary power supply unit 72. The secondary power supply unit 72 generates a voltage necessary for operating the circuits and sensors in the printer 100 based on the DC voltage generated by the primary power supply unit 71. Specifically, the secondary power supply unit 72 is provided with one or a plurality of DCDC converters 72a. For convenience, FIG. 3 shows only one DCDC converter 72a. The DCDC converter 72a includes a switching element (for example, a transistor), a diode, a coil, and a capacitor, and outputs a predetermined voltage. Further, the secondary power source 72 may include a regulator or the like for voltage generation. For example, the secondary power supply unit 72 generates a voltage necessary for driving various CPUs, circuits, and memories, such as DC5V, 3.3V, 2.5V, and 1.8V.

  The voltage generated by the secondary power supply unit 72 is applied to the main control unit 1. When power is supplied to the printer 100 by the power cord C2, the primary power supply 71 and the secondary power supply 72 operate. Therefore, when power is supplied to the printer 100 by the power cord C2, the main control unit 1 (the CPU 11 of the main control unit 1) maintains a driven state.

  The voltage generated by the secondary power supply unit 72 is supplied to a load 100a such as a circuit or a sensor in the printer 100. A plurality of switches 7a are provided to control whether or not to supply power to each load 100a. For convenience, only one switch 7a is shown in FIG. The main control unit 1 turns on / off each switch 7a according to the mode of the printer 100, and turns on / off the power supply to the load 100a such as a circuit or a sensor.

(Mode of printer 100)
Next, each mode in the printer 100 regarding power consumption will be described with reference to FIGS. FIG. 4 is an explanatory diagram for explaining power supply control with respect to the load 100 a portion of the printer 100. FIG. 5 is an explanatory diagram for explaining switching of each mode in the printer 100.

  As shown in FIG. 5, the printer 100 of the present embodiment has three modes regarding power consumption. In other words, the printer 100 includes three modes with different power consumption. Specifically, the printer 100 includes a first power saving mode, a second power saving mode, and a normal mode (sometimes referred to as “Ready mode”).

  As shown in FIG. 4, a switch 7 a for controlling power supply from the secondary power supply unit 72 to the communication unit 9, the storage unit 5, the image processing unit 6, the engine unit 20, the operation panel 4, and the plurality of sensors 8 is provided. It is done. The main control unit 1 controls ON / OFF of the switch 7a, and according to each mode, from the secondary power supply unit 72 to the communication unit 9, the storage unit 5, the image processing unit 6, the engine unit 20, the operation panel 4, a plurality of ON / OFF of power supply to the sensor 8 is switched. A switch 7a is also provided for the motor 3M that rotates various rotating bodies such as the photosensitive drum 31 in the printer 100. The main control unit 1 controls the power supply to the motor 3M by turning on / off the switch 7a for the motor 3M.

  Of the three modes, the normal mode is the mode with the largest power consumption. Specifically, in the normal mode of the printer 100 of the present embodiment, the main control unit 1 (CPU 11) sets all the switches 7a to the ON state, and the communication unit 9, the storage unit 5, the image processing unit 6, the engine unit 20, Power is supplied to the power supply unit 7 for all loads 100a of the printer 100 such as the operation panel 4, the plurality of sensors 8, and the motor 3M. In other words, the normal mode is a mode that keeps the printer 100 ready for use during printing. For example, in the normal mode, electric power is supplied to the heater 37 so that the heating roller 38 is maintained at a temperature suitable for fixing. Even in the normal mode, some switches 7a may be turned off.

  Of the load 100a, the main control unit 1 and the circuit unit 100b such as the communication unit 9, the storage unit 5, the image processing unit 6, and the engine control unit 30 are communicably connected by a bus or the like. In the normal mode, the main control unit 1 and the circuit unit 100b communicate with each other. In the following description, the communication unit 9, the storage unit 5, the image processing unit 6, the engine control unit 30, and the like include a CPU, a microcomputer, a setting storage memory, and a register (storage element). These portions are referred to as “circuit portion 100b”. In other words, the communication unit 9, the storage unit 5, the image processing unit 6, the engine control unit 30, etc. as the circuit unit 100 b each store setting values and data instructed by the main control unit 1 such as a memory and a register in a nonvolatile manner. Storage elements (storage unit 5, storage element 301, storage element 62, storage element 91, see FIG. 2).

  Moreover, when shifting from the first power saving mode or the second power saving mode to the normal mode, the main control unit 1 supplies power to the circuit unit 100b in the circuit unit 100b that has stopped power supply. Then, when the main control unit 1 starts supplying power to the circuit unit 100b, the main control unit 1 communicates with the circuit unit 100b, writes a setting value, data, and the like in the memory element included in each circuit unit 100b, and activates it.

  Of the three modes, the first power saving mode is the mode with the lowest power consumption. Specifically, in the first power saving mode, the main control unit 1 (CPU 11) turns off all the switches 7a, the communication unit 9, the storage unit 5, the image processing unit 6, the engine unit 20, the operation panel 4, and a plurality of The power supply 7 stops power supply to all loads 100a such as the sensor 8 and the motor 3M. Note that some of the main control unit 1 and the CPU 11 stop driving for power saving, but some continue to drive. In other words, the first power saving mode is a mode in which only the main control unit 1 (CPU 11) is activated. In the first power saving mode, power is not supplied to the heater 37. In addition, since power is not supplied to the entire circuit unit 100b, communication between the main control unit 1 and the circuit unit 100b is not performed in the first power saving mode.

  Of the three modes, the second power saving mode is a mode that consumes less power than the normal mode and consumes more power than the first power saving mode. Specifically, in the second power saving mode, the main control unit 1 (CPU 11) turns off some of the predetermined switches 7a among the switches 7a.

  In the printer 100 of the present embodiment, in the second power saving mode, the main control unit 1 stops supplying power to the portion used for printing. Specifically, in the second power saving mode, the main control unit 1 turns on the switch 7a for the communication unit 9, the storage unit 5, the operation panel 4, etc., and causes the power supply unit 7 to supply power to these parts. . In the second power saving mode, the main control unit 1 turns off the switch 7a for the parts used for printing, such as the image processing unit 6, the engine unit 20 (engine control unit 30), the motor 3M, and the like. The power supply is stopped by the power supply unit 7. In the second power saving mode, which switch 7a is turned off and which switch 7a is kept on can be appropriately determined.

  Here, the printer 100 is provided with a plurality of sensors 8 as the load 100a. The sensor 8 is roughly classified into two types: a first sensor 8a that does not supply power in the second power saving mode, and a second sensor 8b that supplies power even in the second power saving mode.

  For example, the first sensor 8a is a registration sensor 81, a discharge sensor 82, a temperature sensor 83 of the fixing unit 3b, or the like. The registration sensor 81 is a sensor for detecting the arrival and passage of the sheet to the registration roller pair 25 (see FIG. 1, for example, an optical sensor). The discharge sensor 82 is a sensor for detecting whether the paper reaches the installation position and is properly discharged to the discharge tray 22 (see FIG. 1, for example, an optical sensor). The temperature sensor 83 is a sensor for detecting the temperature of the heating roller 38 (see FIG. 1, for example, including a thermistor). Since the normal mode is restored when printing, these sensors are not used in the second power saving mode. As described above, in the printer 100 of the present embodiment, in the second power saving mode, power supply to some sensors is stopped to reduce power consumption.

  For example, the second sensor 8 b is a sensor for detecting an operation on the printer 100 such as a cassette sensor 84 or a cover sensor 85. The cassette sensor 84 is a sensor for detecting removal and attachment of the paper feed unit 2a (see FIG. 1, for example, an interlock switch). The cover sensor 85 is a sensor for detecting opening and closing of the upper cover and the front cover of the printer 100 (see FIG. 1, for example, an interlock switch). It may be desirable to detect an operation on the printer 100 even in the second power saving mode. Therefore, in the printer 100 of the present embodiment, power supply to some sensors is continued in the second power saving mode.

  The sensor described above is an example of a sensor provided in the printer 100, and another sensor may be provided in the printer 100 as the plurality of sensors 8. In the second power saving mode, it is possible to appropriately determine which sensor 8 of the plurality of sensors 8 is stopped from supplying power and which sensor 8 is supplied with power.

  Next, transition conditions between the modes will be described with reference to FIG. When the removed power cord C2 is plugged into the outlet C1, first, the main control unit 1 sets the mode of the printer 100 to the first power saving mode. In other words, the mode of the printer 100 starts from the first power saving mode.

  As shown in FIG. 3, power is applied to the activation switch 10 as long as power is supplied to the printer 100 (when the power cord C2 is connected to the outlet C1). Thereby, regardless of each mode of the normal mode, the first power saving mode, and the second power saving mode, the activation switch 10 receives an input of a mode switching instruction from the user. In response to the output of the start switch 10, the main control unit 1 recognizes that a mode switching instruction has been made by touching the start switch 10.

  When the start switch 10 is pressed in the first power saving mode, the main control unit 1 sets the printer 100 to the normal mode (arrow A in FIG. 5).

  After entering the normal mode, the main control unit 1 controls each switch 7a when a certain transition condition is satisfied to change the printer 100 from the normal mode to the first power saving mode or the second power saving mode. In the printer 100 of this embodiment, when the start switch 10 is pressed in the normal mode, the main control unit 1 determines that the condition for shifting from the normal mode to the first power saving mode is satisfied. In this case, the main control unit 1 turns off all the switches 7a. Then, the main control unit 1 puts the printer 100 in the first power saving mode (arrow B in FIG. 5). As a result, the power consumption of the printer 100 is minimized.

  Further, in the printer 100 of the present embodiment, the main control unit 1 does not perform printing from a predetermined timing start time, does not receive printing data from the computer 200, and does not operate the printer 100. When the predetermined second power saving mode transition time elapses, it is determined that the second power saving mode transition condition is satisfied from the normal mode. Further, when the power saving switch 43a provided on the operation panel 4 or the like is pressed, the main control unit 1 determines that the condition for shifting to the second power saving mode is satisfied. When the condition for shifting to the second power saving mode is satisfied, the main control unit 1 turns off some of the predetermined switches 7a to put the printer 100 in the second power saving mode (arrow in FIG. 5). C).

  In the second power saving mode, when the power saving switch 43a is pressed, the main control unit 1 determines that the condition for shifting from the second power saving mode to the normal mode is satisfied. In addition, when printing data is input to the communication unit 9, the main control unit 1 may determine that the condition for shifting from the second power saving mode to the normal mode is satisfied. Alternatively, when the main control unit 1 recognizes an operation on the printer 100 such as loading / unloading of the paper feeding unit 2a and opening / closing of the cover based on the first sensor 8a, the main control unit 1 changes from the second power saving mode to the normal mode. It may be determined that the transition condition to is satisfied. When the condition for shifting from the second power saving mode to the normal mode is satisfied, the main control unit 1 turns on some of the switches 7a that have been in the OFF state and puts the printer 100 into the normal mode (in FIG. 5). Arrow D).

  In the second power saving mode, when the start switch 10 is pressed, the main control unit 1 determines that the condition for shifting from the second power saving mode to the first power saving mode is satisfied. In addition, after entering the second power saving mode, a predetermined automatic stop time (without the printing data being input to the communication unit 9 and without recognizing the operation on the printer 100 based on the first sensor 8a). For example, when several tens of minutes have elapsed, the main control unit 1 determines that the condition for shifting from the second power saving mode to the first power saving mode is satisfied. When the transition condition from the second power saving mode to the first power saving mode is satisfied, the main control unit 1 turns off some of the switches 7a that have been partly turned on and turns the printer 100 to the first power saving mode. The mode is set (arrow E in FIG. 5).

(Startup flow when the power cord C2 is inserted)
Next, an example of a startup flow when the power cord C2 is inserted in the printer 100 of the present embodiment (when the power cord C2 is connected to the outlet C1) will be described with reference to FIG. FIG. 6 is a timing chart showing an example of a startup flow when the power cord C2 is inserted.

  First, in FIG. 6, the output level of the primary power supply 71 (switching power supply 71a) is indicated by a solid line. In FIG. 6, the output level of the secondary power source 72 is indicated by a two-dot chain line.

  When the power cord C2 is connected to the outlet C1 (at time t1 in FIG. 6), the primary power source 71 starts operating. Then, the output of the primary power supply 71 increases. The primary power supply unit 71 outputs a predetermined output voltage.

  When the output of the primary power supply unit 71 increases to a voltage that can drive the secondary power supply unit 72, the secondary power supply unit 72 starts driving (at time t2 in FIG. 6). Thereafter, the output of the secondary power supply 72 increases. Then, the secondary power supply unit 72 outputs a predetermined output voltage. Thereby, electric power is supplied to the main control unit 1, the main control unit 1 is activated, and the main control unit 1 is in a state of operating. The start switch 10 is also in a state where a voltage is applied.

  And t3 in FIG. 6 has shown the point in time when the starting switch 10 was pushed. When the start switch 10 is pressed, the main control unit 1 turns on all the switches 7a and sets the mode of the printer 100 to the normal mode. As a result, power supply from the secondary power supply unit 72 to the communication unit 9, the storage unit 5, the image processing unit 6, the engine unit 20, the operation panel 4, the plurality of sensors 8, and the like is started (at t4 in FIG. 6). Time). The main control unit 1 communicates with the communication unit 9, the storage unit 5, the image processing unit 6, the engine unit 20, the operation panel 4, the plurality of sensors 8, and the like, while the communication unit 9, the storage unit 5, the image processing unit. 6. The engine unit 20, the operation panel 4, and the plurality of sensors 8 are set and activated. In addition, the main control unit 1 communicates with the circuit unit 100b such as the communication unit 9, the storage unit 5, the image processing unit 6, and the engine control unit 30 to set operation values for each storage element of the circuit unit 100b. Register the data. Then, the main control unit 1 activates the circuit unit 100b and the like. When the engine control unit 30 of the engine unit 20 is activated, a voltage can be applied to the motor 3M (at time t5 in FIG. 6). Thus, when the power cord C2 is connected to the outlet C1, the main control unit 1 is activated.

(Voltage drop and problems when power supply to the printer 100 stops)
Next, an example of the flow of the voltage drop when the power supply in the printer 100 of the present embodiment is stopped will be described with reference to FIG. FIG. 7 is a timing chart illustrating an example of a voltage drop flow when power supply to the printer 100 is stopped.

  First, in FIG. 7, the output level of the primary power supply 71 (switching power supply 71a) is indicated by a solid line. In FIG. 7, the output level of the secondary power source 72 is indicated by a two-dot chain line.

  A time point t6 in FIG. 7 is a time point when power supply to the printer 100 is stopped. The power supply to the printer 100 is stopped due to a power failure or the power cord C2 being disconnected from the outlet C1.

  The main control unit 1 recognizes the stop of power supply to the printer 100 based on the output (zero cross signal) of the zero cross signal generation unit 71b. While the power cord C2 is connected to the outlet C1, the zero cross signal generation unit 71b continues to output the zero cross signal to the main control unit 1. For example, if the frequency of the power source (for example, commercial power source) is 50 Hz, the zero cross signal generation unit 71b outputs a 100 Hz zero cross signal and a 60 Hz zero cross signal if the frequency is 60 Hz.

  The main control unit 1 recognizes that the power cord C2 is disconnected from the outlet C1 when the zero-cross signal continues for a predetermined power supply stop detection time after the zero-cross signal disappears (at t7 in FIG. 7). Time). The power supply stop detection time can be arbitrarily determined. For example, the power supply stop detection time is set to a time corresponding to a plurality of cycles of the zero cross signal.

  Then, as shown in FIG. 7, when the power supply to the printer 100 is stopped, the output of the primary power supply unit 71 and the secondary power supply unit 72 starts to drop.

  However, since the stored energy remains in the capacitors and coils of the primary power supply unit 71 and the secondary power supply unit 72, the primary power supply units 71 and 2 immediately after the power supply to the printer 100 is stopped. The output voltage value of the next power supply unit 72 does not become zero. In other words, even if the power supply to the printer 100 is stopped, the main control unit 1 and the circuit unit 100b of the load 100a remain in the main control unit 1 and the load 100a until the energy stored in the primary power supply unit 71 and the secondary power supply unit 72 decreases. Keep driving.

  Specifically, in FIG. 7, a point in time when the output of the primary power supply unit 71 disappears when the printer 100 is in the normal mode is indicated by a time t8, and the transition is indicated by a solid line. In FIG. 7, the time point when the output of the secondary power supply unit 72 disappears when the printer 100 is in the normal mode is indicated by a time point t9, and the transition is indicated by a solid line. Also, t10 indicates the time when the output of the secondary power source 72 decreases as the voltage is lower than the voltage required for driving the main control unit 1 and the circuit unit 100b.

  Further, in FIG. 7, the time point when the output of the primary power source 71 disappears when the printer 100 is in the second power saving mode is indicated by a time point t11, and the transition is indicated by a solid line. In FIG. 7, the time point when the output of the secondary power supply unit 72 disappears when the printer 100 is in the normal mode is indicated by a time point t12, and the transition is indicated by a solid line. In addition, t13 indicates a time point when the output of the secondary power source 72 decreases as the voltage is lower than the voltage required for driving the main control unit 1 and the circuit unit 100b.

  Further, in FIG. 7, the time point when the output of the primary power supply unit 71 disappears when the printer 100 is in the first power saving mode is indicated by a time point t14, and the transition is indicated by a solid line. In FIG. 7, the time point at which the output of the secondary power source 72 disappears when the printer 100 is in the normal mode is indicated by a time t15, and the transition is indicated by a solid line. In addition, t16 indicates a time point when the output of the secondary power supply unit 72 decreases as it falls below the voltage required for driving the main control unit 1 and the circuit unit 100b.

  As shown in FIG. 7, as the power consumption increases, the output of the primary power supply unit 71 and the secondary power supply unit 72 decreases earlier when the power supply to the printer 100 is stopped. In the printer 100 of the present embodiment, when the power supply to the printer 100 is stopped, the output reduction of the primary power supply unit 71 and the secondary power supply unit 72 is the fastest in the normal mode, and then the second power saving mode is fast, The first power saving mode is the slowest.

  Each power saving mode consumes less power. Therefore, the time from when the power supply to the printer 100 is stopped until the output of the primary power supply unit 71 or the secondary power supply unit 72 is reduced and the load 100a such as the main control unit 1 or the circuit unit 100b stops operating. Is longer than normal mode. In particular, in the first power saving mode, the main controller 1 (the CPU 11) consumes power only. For this reason, in the first power saving mode, it may take several tens of seconds for the outputs of the primary power supply 71 and the secondary power supply 72 to decrease.

  Here, there is a case where the user unplugs the power cord C2 from the outlet C1 and stops the power supply to the printer 100 at his / her own will. In such a case, there are few cases in which the start switch 10 is pushed after the power cord C2 is removed.

  On the other hand, the power cord C2 may be pulled out of the outlet C1 by someone's feet or a power failure may occur, and the power supply to the printer 100 may stop unintentionally. Thus, when the power supply to the printer 100 is stopped unintentionally, the user may press the start switch 10 without knowing that the power supply is stopped.

  Even if the power supply to the printer 100 is stopped, the main control unit 1 may be in an operating state. Therefore, conventionally, when the power supply to the printer 100 is stopped and the main control unit 1 is operating, when the start switch 10 is pressed, the main control unit 1 starts a process of shifting the printer 100 to the normal mode. Resulting in.

  In order to shift to the normal mode, the main control unit 1 turns on each switch 7a and starts supplying power to the circuit unit 100b (communication unit 9, storage unit 5, image processing unit 6, engine control unit 30, etc.). Then, the main control unit 1 causes the circuit unit 100 b such as the communication unit 9, the storage unit 5, the image processing unit 6, and the engine control unit 30 to perform activation processing. In the start-up process, the main control unit 1 transmits a signal to the circuit unit 100b, and causes the circuit unit 100b to perform initialization, set value setting and registration in each storage element in the circuit unit 100b, and the like.

  However, when the power supply to the printer 100 is stopped, the output of the secondary power supply unit 72 is reduced to a level at which the main control unit 1 and the circuit unit 100b cannot be driven before the activation of the circuit unit 100b is completed. There is. If it does so, the starting process in the communication part 9, the memory | storage part 5, the image process part 6, the engine control part 30, etc. will be forcedly complete | finished in a halfway state. At this time, an incorrect set value is written (non-volatilely registered) in a storage element (memory, register, etc.) included in the communication unit 9, the storage unit 5, the image processing unit 6, the engine control unit 30, and the like. May remain). In particular, in a situation where the output of the secondary power supply unit 72 is reduced and the voltage applied to the main control unit 1 is small, the signal generated by the main control unit 1 becomes unstable and outputs a signal including an error. Thus, an incorrect value may be stored in any storage element of the circuit unit 100b in a nonvolatile manner.

  Then, when the circuit unit 100 b such as the communication unit 9, the storage unit 5, the image processing unit 6, and the engine control unit 30 is activated next when the first power saving mode is shifted to the normal mode, There is a case in which the circuit unit 100b cannot be normally activated due to being registered in a memory element such as a memory or a register in the memory 100b.

  Therefore, in the printer 100 according to the present embodiment, when the power supply to the printer 100 is detected to stop in the power saving mode (the first power saving mode and the second power saving mode), the main control unit 1 switches to the normal mode. Even if it recognizes that there was a transition instruction (even if it recognizes that start switch 10 was pushed in the 1st power saving mode, and that power saving switch 43a was pushed in the 2nd power saving mode), In the circuit unit 100b such as the communication unit 9, the storage unit 5, the image processing unit 6, and the engine control unit 30, the power supply from the power supply unit 7 to the part where the power supply is stopped is not started, and halfway The circuit unit 100b is not activated. In other words, in other words, the main control unit 1 may not start power supply to all of the circuit units 100b even when there is an instruction to shift to the normal mode.

(When the start switch 10 in the first power saving mode is pressed)
Next, referring to FIG. 7, the flow of control when the start switch 10 is pressed in the first power saving mode with the power supply to the printer 100 stopped using FIG. An example will be described. FIG. 8 is a flowchart illustrating an example of a control flow when the start switch 10 is pressed in the first power saving mode with the power supply to the printer 100 stopped.

  First, the start of FIG. 8 is the first power saving mode, and is the time when the main control unit 1 recognizes that the power supply to the printer 100 is stopped based on the zero cross signal and the start switch 10 is pressed.

  First, the main control unit 1 instructs the start switch 10 to shift to the normal mode from when the stop of the power supply to the printer 100 is detected until the first non-start time T1 for the first power saving mode elapses. Even if accepted, power supply to the entire circuit unit 100b such as the communication unit 9, the storage unit 5, the image processing unit 6, and the engine control unit 30 is not started (step # 11).

  Then, until the first non-activation time T1 elapses from when the stop is detected, the main control unit 1 performs a predetermined shutdown process for safely shutting down the power control unit (step # 12). For example, the data stored in the memory in the CPU 11 in the control unit is stored in the nonvolatile memory provided in the main control unit 1.

  Here, when the stop is detected, it is the time when the main control unit 1 recognizes the stop of the power supply to the printer 100 due to a power failure or the disconnection of the outlet C1. Specifically, the stop detection time is the time when a predetermined stop detection time for power supply has elapsed after the zero cross signal disappears.

  Further, the first non-starting time T1 is a predetermined time. The first non-startup time T1 is determined based on the result of measuring the time from when the power supply to the printer 100 is detected to stop until the output of the primary power supply unit 71 becomes zero in the first power saving mode by experiment or the like. (Time from t7 to t15 in FIG. 7). For example, the first non-activation time T1 is several tens of seconds. The first inactivation time T1 is the time from when the stop of power supply to the printer 100 is detected in the first power saving mode until the output of the primary power supply unit 71 decreases to a level at which the main control unit 1 cannot operate. (Time from t7 to t16 in FIG. 7) may be determined as a guide.

  If the main control unit 1 has stopped driving when the first non-activation time T1 has elapsed from the detection of the stop, this flow ends (No in step # 13 → end).

  On the other hand, power is intermittently and intermittently supplied to the printer 100 due to the connection / disconnection of the power cord C2 to / from the outlet C1 or the contact failure of the power cord C2, and the first non-activation time T1 has elapsed from the time when the stop was detected. In some cases, the main control unit 1 is driven. Further, the power consumption of the main control unit 1 is affected by the contents of processing at that time, and there is a possibility that the main control unit 1 is operating even when the power cord C2 is disconnected from the outlet C1.

  Therefore, if the main control unit 1 is driven when the first non-activation time T1 has elapsed from the time of detecting the stop (Yes in Step # 13), the main control unit 1 includes the communication unit 9, the storage unit 5, and the image processing unit. 6. The circuit unit 100b such as the engine control unit 30 is kept in an unactivated state (step # 14). Then, main controller 1 measures the output voltage value of primary power supply 71 (step # 15).

  Then, the main control unit 1 includes the circuit unit 100b (the communication unit 9, the storage unit 5, and the image processing unit 6) having the smallest drive voltage of the primary control unit 1 or the circuit unit 100b. Then, it is confirmed whether or not the engine control unit 30 or the like is not driven (step # 16). In other words, the main control unit 1 checks whether or not the output voltage value of the primary power supply unit 71 has become so large that the circuit unit 100b cannot be substantially activated even when the activation process is started (step # 16). ).

  If the main control unit 1 is operated and the circuit unit 100b is not large enough to be activated (No in step # 16), the main control unit 1 also stops driving, and the flow ends.

  On the other hand, if the magnitude of the output voltage of the primary power supply unit 71 is still large enough to operate the main control unit 1 and activate the circuit unit 100b, the main control unit 1 outputs the output of the primary power supply unit 71. It is checked whether the voltage value has reached a predetermined level (recovered) (step # 17). For example, the predetermined size can be set to a size capable of driving the load 100a having the highest driving voltage among the loads 100a including the circuit unit 100b. For example, the main control unit 1 checks whether or not the output voltage value of the primary power supply unit 71 has been restored to DC 24V that can drive the motor 3M.

  If the output voltage value of primary power supply unit 71 is not a predetermined value (No in step # 17), the flow returns to step # 14. On the other hand, if the output voltage value of the primary power supply unit 71 has been restored to a predetermined level (No in step # 17), the main control unit 1 resumes supplying sufficient power to the printer 100, It is determined that there is no problem even if the printer 100 is set to the normal mode. The main control unit 1 controls each switch 7a to start and start power supply to the circuit unit 100b (communication unit 9, storage unit 5, image processing unit 6, engine control unit 30, etc.) (step #). 18 → End). In this manner, it is confirmed whether sufficient power supply to the printer 100 has been resumed, and after confirming that the power supply is not halfway started, the circuit unit 100b is started.

(When the power saving switch 43a is pressed in the second power saving mode)
Next, referring to FIG. 9, the flow of control when the power saving switch 43a is pressed in the second power saving mode with the power supply to the printer 100 stopped, with reference to FIG. An example will be described. FIG. 9 is a flowchart illustrating an example of a control flow when the power saving switch 43a is pressed in the second power saving mode with the power supply to the printer 100 stopped.

  First, the start of FIG. 9 is the second power saving mode, when the power saving switch 43a is pressed while the main control unit 1 recognizes that the power supply to the printer 100 is stopped based on the zero cross signal. is there. In other words, when the main control unit 1 determines that the condition for shifting from the second power saving mode to the normal mode is satisfied by pressing the power saving switch 43a in the second power saving mode.

  First, the main control unit 1 issues an instruction to shift to the normal mode with the power saving switch 43a from the time when the stop of the power supply to the printer 100 is detected until the second non-start time T2 for the second power saving mode elapses. Even if it is received, a part of the circuit unit 100b such as the communication unit 9, the storage unit 5, the image processing unit 6, and the engine control unit 30 where the power supply from the power source unit 7 is stopped in the second power saving mode ( In the printer 100 of the present embodiment, power supply to the image processing unit 6 and the engine control unit 30) is not started (step # 21).

  Then, until the second non-activation time T2 elapses from when the stop is detected, the main control unit 1 performs a predetermined shutdown process for safely shutting down the power control unit (step # 22). For example, it is stored in a volatile manner in the main control unit 1, the communication unit 9, and the like, and the nonvolatile memory of the storage unit 5 stores data to be saved.

  The second non-activation time T2 is a predetermined time. First, based on the difference in power consumption between the first power saving mode and the second power saving mode, the second non-activation time T2 is shorter than the first non-activation time T1. In other words, the first non-activation time T1 is longer than the second non-activation time T2.

  The second non-activation time T2 is an experiment or the like, which is a result of measuring the time from when the power supply to the printer 100 is detected to stop until the output of the primary power source 71 becomes 0 in the second power saving mode. It can be determined based on (time from t7 to t12 in FIG. 7). For example, the second non-activation time T2 is about 10 seconds. The second inactivation time T2 is the time from when the stop of power supply to the printer 100 is detected in the second power saving mode until the output of the primary power supply unit 71 decreases to a level at which the main control unit 1 cannot operate. (Time from t7 to t16 in FIG. 7) may be determined as a guide.

  If the main control unit 1 has stopped driving when the second non-activation time T2 has elapsed from the detection of the stop, this flow ends (No in step # 23 → end).

  In addition, power is intermittently and intermittently supplied to the printer 100 due to plugging / unplugging of the power cord C2 into / from the outlet C1, contact failure of the power cord C2, etc. The main control unit 1 may be driven. Further, since the power consumption of the main control unit 1 is affected by the processing contents at that time, there is a possibility that the main control unit 1 is operating even when the power cord C2 is disconnected from the outlet C1.

  Therefore, if the main control unit 1 is driven when the second non-activation time T2 has elapsed from the time of detecting the stop (Yes in step # 23), the main control unit 1 includes the image processing unit 6 in the circuit unit 100b, A portion that is not supplied with power in the second power saving mode such as the engine control unit 30 is kept in an unstarted state (step # 24). Step # 25 and subsequent steps are the same as step # 15 to step # 18 in the first power saving mode, but will be described below.

  Main controller 1 measures the output voltage value of primary power supply 71 (step # 25). Then, the main control unit 1 includes the circuit unit 100b (the communication unit 9, the storage unit 5, and the image processing unit 6) having the smallest drive voltage of the primary control unit 1 or the circuit unit 100b. Then, it is confirmed whether or not the engine control unit 30 or the like is not driven (step # 26). In other words, the main control unit 1 checks whether or not the output voltage value of the primary power supply unit 71 has become so large that the circuit unit 100b cannot be substantially activated even when the activation process is started (step # 26). ).

  If the main control unit 1 is operated and the circuit unit 100b becomes so large that the circuit unit 100b cannot be substantially activated (No in step # 26), the main control unit 1 also stops driving, and the flow ends.

  On the other hand, if the main control unit 1 is operated and the circuit unit 100b is kept large enough to be activated, the main control unit 1 has a predetermined output voltage value of the primary power supply unit 71. (Recovered) is confirmed (step # 27). The predetermined size is set such that the load 100a having the highest drive voltage among the loads 100a including the circuit unit 100b can be driven. For example, the main control unit 1 checks whether or not the output voltage value of the primary power supply unit 71 has been restored to DC 24V that can drive the motor 3M.

  If the output voltage value of primary power supply 71 is not a predetermined level (No in step # 27), the flow returns to step # 24. On the other hand, if the output voltage value of the primary power supply unit 71 has recovered to a predetermined level (No in step # 27), the main control unit 1 resumes supplying sufficient power to the printer 100, It is determined that there is no problem even if the printer 100 is set to the normal mode. Then, the main control unit 1 controls each switch 7a to supply power to the circuit unit 100b (portion where power supply is stopped in the second power saving mode such as the image processing unit 6 and the engine control unit 30). Start and start (step # 28 → end). In this manner, it is confirmed whether sufficient power supply to the printer 100 has been resumed, and after confirming that the power supply is not halfway started, the circuit unit 100b is started.

In this way, the image forming apparatus (printer 100) of the present embodiment performs a startup process when power supply is started, and operates by receiving power supply, the circuit unit 100b (communication unit 9, storage unit 5, image). A processing unit 6, an engine control unit 30, etc.), an operation unit (start switch 10) for receiving a mode switching instruction between the normal mode and the power saving mode that reduces power consumption in the image forming apparatus more than the normal mode,
A power cord C2 connected to an external supply source for receiving power from an external power source, and a detection unit for detecting whether or not power is being supplied to the image forming apparatus by the power cord C2. (Zero-cross signal generation unit 71b) and ON / OFF of power supply to the circuit unit 100b are controlled, power is supplied to the circuit unit 100b in the normal mode, and all or a part of the circuit units 100b in the power saving mode. Power supply to the circuit unit 100b is started and a signal is exchanged with the activated circuit unit 100b when the operation unit issues a transition instruction that is an instruction to switch from the power saving mode to the normal mode. In the state where the power input to the image forming apparatus via the power control unit (main control unit 1) that performs the power supply and the power cord C2 is converted and the power cord C2 is connected to the supply source, A power supply unit 7 for supplying power to the circuit unit 100b that supplies power to the circuit unit 100b and operates the power control unit, and the power control unit turns on the power supply. When the stop of power supply to the used image forming apparatus is detected, even when the operation unit receives a shift instruction, the power supply to the circuit unit 100b is not started and the circuit unit 100b is not activated.

  Thus, in a state where power supply to the image forming apparatus (printer 100) is stopped due to a power failure or the power cord C2 being dropped, the circuit unit 100b (communication unit 9, storage unit 5, image processing unit 6, engine control unit) 30) or the like can be eliminated. Therefore, it is possible to prevent halfway start-up processing from being performed in the circuit unit 100b. Even if the power supply to the image forming apparatus is stopped, an erroneous setting value may be registered in the memory in the circuit unit 100b at the next start-up (at the start of the next power supply), or the circuit itself The abnormality that the circuit unit 100b does not start due to the damage can be eliminated. And the circuit part 100b can be started reliably and normally at the time of the next starting (at the time of the next electric power supply start).

  Further, the power control unit (main control unit 1) does not stop the circuit unit 100b (communication unit 9) even if the operation unit (startup switch 10) accepts a transition instruction until a predetermined non-startup time elapses after the stop detection. The power supply to the storage unit 5, the image processing unit 6, the engine control unit 30, etc.) is not started and the circuit unit 100b is not activated. As a result, it is possible to ensure that the power supply to the circuit unit 100b is not started during the non-startup time from when the stop is detected. Therefore, it is possible to reliably avoid a halfway start-up process of the circuit unit 100b. The “non-startup time” is a time that can be arbitrarily determined, and the time required for the output voltage value of the power supply unit 7 to drop after the power supply to the image forming apparatus (printer 100) is stopped is measured in advance. It can be determined by doing.

After the power supply to the image forming apparatus (printer 100) is stopped, the output voltage value of the power supply unit 7 is changed to the power control unit (main control unit 1) or the circuit unit 100b (communication unit 9, storage unit 5, image processing unit). 6, the time until the driving voltage of the engine control unit 30 falls below the driving voltage varies depending on the power consumption in the image forming apparatus when the supply is stopped. As the power consumption in the image forming apparatus at the time of the supply stop increases, the energy stored in the power supply unit 7 is consumed earlier, and the time until the output voltage value of the power supply unit 7 falls below the drive voltage of the circuit unit 100b becomes shorter. . Therefore, in the image forming apparatus according to the present embodiment, as the power saving mode, the first power saving mode and the circuit unit 100b that supplies power more than the normal mode have a larger number of circuit units 100b that supply power than the first power saving mode. The operation unit (start switch 10) accepts an instruction to shift from the first power saving mode to the normal mode and an instruction to shift from the second power saving mode to the normal mode. When the power control unit (main control unit 1) detects that power supply to the image forming apparatus (in the first power saving mode is detected), the first non-start time for the first power saving mode is detected from the time when the stop is detected. Even if the operation unit accepts the transition instruction until T1 elapses, power supply to the circuit unit 100b is not started (power supply to all of the circuit unit 100b is not started), and power supply to the image forming apparatus is stopped. The second was detected In the power mode, the first power supply to the circuit unit 100b is not started even if the operation unit accepts the transition instruction until the second non-activation time T2 for the second power saving mode elapses from when the stop is detected. The non-activation time T1 is longer than the second non-activation time T2. Thereby, the non-activation time is changed according to the power consumption in each power saving mode, so even if there are multiple types of power saving modes, A halfway start-up process can be reliably avoided.

  The “first inactivation time T1” can be arbitrarily determined. In the first power saving mode, the power supply 7 outputs after the power supply to the image forming apparatus (printer 100) is stopped. The time until the voltage value drops to such an extent that the power control unit (main control unit 1) and the circuit unit 100b (communication unit 9, storage unit 5, image processing unit 6, engine control unit 30 and the like) are not activated in advance. It can be determined by measuring. Further, the “second non-starting time T2” is a time that can be arbitrarily determined, and the output voltage value of the power supply unit 7 after the power supply to the image forming apparatus is stopped in the second power saving mode is The time until the power control unit and the circuit unit 100b are reduced to such an extent that they do not start can be determined by measuring in advance.

The power control unit (main control unit 1) measures the magnitude of the output voltage of the power supply unit 7, and the power control unit or circuit unit 100b (communication unit 9, memory) from when the output voltage value of the power supply unit 7 is detected to be stopped. Circuit unit 100b even if the operation unit (start switch 10) accepts the transition instruction until the circuit unit 100b having the smallest driving voltage is driven to a size that does not drive among the unit 5, the image processing unit 6, the engine control unit 30, and the like. The circuit unit 100b is not activated without starting the power supply to the circuit.
Thereby, in a state where the power supply to the image forming apparatus (printer 100) is stopped, the power supply to the circuit unit 100b is reliably supplied until the output voltage value of the power supply unit 7 falls below the drive voltage of the circuit unit 100b. You can prevent it from starting.

  In addition, after the power control unit (main control unit 1) detects the stop, the circuit unit 100b (communication unit 9, storage unit 5, image processing) is restored after the output voltage value of the power source unit 7 is restored to a predetermined level. Power supply to the unit 6, the engine control unit 30 and the like) to start the circuit unit 100b. As a result, when the output voltage value of the external power source supplied to the image forming apparatus (printer 100) is unstable, or due to poor contact due to partial disconnection of the power cord C2, the insertion and removal of the power cord C2 seems to be repeated. Even in such a state, it is possible to reliably avoid a halfway start-up process of the circuit unit 100b.

  In addition, the power control unit (main control unit 1) is connected to the power control unit and the circuit unit 100b (communication unit 9, storage unit 5, image processing unit 6, engine control unit) from when the stop is detected until the non-start time elapses 30 or the like), a predetermined shutdown process for safely shutting down one or both of them is performed. As a result, even if power supply to the image forming apparatus (printer 100) is suddenly interrupted due to a power failure or disconnection of the power cable from the outlet C1, the circuit unit 100b and the like are normally started when the next image forming apparatus is started. Can be made.

  The embodiment of the present invention has been described above, but the scope of the present invention is not limited to this, and various modifications can be made without departing from the spirit of the invention.

  The present invention is applicable to an image forming apparatus having a power saving mode and a normal mode, and including an operation unit for switching from the power saving mode to the normal mode.

DESCRIPTION OF SYMBOLS 100 Printer (image forming apparatus) 100a Load 100b Circuit part 1 Main control part (power control part)
30 Engine control unit (circuit unit 100b)
5 Storage Unit (Circuit Unit 100b) 6 Image Processing Unit (Circuit Unit 100b)
7 Power supply unit 71b Zero cross signal generation unit (detection unit)
9 Communication unit (circuit unit 100b) 10 Start switch (operation unit)
T1 First non-start time T2 Second non-start time C2 Power cord

Claims (6)

When power supply is started, a startup process is performed, and a circuit unit that operates by receiving power supply;
An operation unit that receives a mode switching instruction between the normal mode and a power saving mode that reduces power consumption in the image forming apparatus than the normal mode;
A power cord connected to an external source to receive power from an external power source;
A detection unit for detecting whether power is supplied to the image forming apparatus by the power cord;
Controls ON / OFF of power supply to the circuit unit, performs power supply to the circuit unit in the normal mode, stops power supply to all or part of the circuit units in the power saving mode, Power control for starting the power supply to the circuit unit and exchanging signals with the activated circuit unit when an instruction to switch from the power saving mode to the normal mode is given by the operation unit And
In the state where the power input to the image forming apparatus via the power cord is converted and the power cord is connected to the supply source, power is supplied to the power control unit to operate the power control unit, or A power supply unit that supplies power to the circuit unit in which the power control unit turns on the power supply, and
The power control unit supplies power to the circuit unit even when the operation unit receives the transition instruction at the time of detection of a stop, that is, when the stop of power supply to the image forming apparatus using the detection unit is detected. The image forming apparatus is characterized in that the circuit unit is not activated without starting.   The power control unit starts the circuit unit without starting power supply to the circuit unit even when the operation unit receives the transition instruction until a predetermined non-start time elapses from the time when the stop is detected. The image forming apparatus according to claim 1, wherein the image forming apparatus is not used. As the power saving mode, there are a first power saving mode and the second power saving mode in which the number of circuit units supplying power is larger than that in the first power saving mode and the number of circuit units supplying power is smaller than that in the normal mode. Has a power mode,
The operation unit accepts the transition instruction from the first power saving mode to the normal mode and the transition instruction from the second power saving mode to the normal mode,
When the stop of power supply to the image forming apparatus is detected in the first power saving mode, the power control unit passes the first non-start time for the first power saving mode from the detection of the stop. Even if the operation unit accepts the shift instruction, the supply of power to the circuit unit is not started, and the stop of the power supply to the image forming apparatus is detected when the second power saving mode is detected. From the time of detection until the second non-activation time for the second power saving mode elapses, the operation unit does not start supplying power to the circuit unit even if it receives the transition instruction,
The image forming apparatus according to claim 2, wherein the first non-start time is longer than the second non-start time.   The power control unit measures the magnitude of the output voltage of the power supply unit, and the circuit unit having the smallest drive voltage of the power control unit or the circuit unit from the time when the output voltage value of the power supply unit is detected is detected. The power supply to the circuit unit is not started and the circuit unit is not started up even if the operation unit receives the transition instruction until the size becomes not driven. The image forming apparatus described in the item.   After detecting the stop, the power control unit starts supplying power to the circuit unit when the output voltage value of the power supply unit recovers to a predetermined magnitude. The image forming apparatus according to claim 4, wherein the image forming apparatus is activated.   The power control unit is a predetermined shutdown time for safely shutting down one or both of the power control unit and the circuit unit between the time when the stop is detected and the time when the non-starting time elapses. 6. The image forming apparatus according to claim 2, wherein processing is performed.

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